The gtk+ package contains the GIMP ToolKit (GTK+), a library for
creating graphical user interfaces for the X Window System. GTK+ was
originally written for the GIMP (GNU Image Manipulation Program) image
processing program, but is now used by several other programs as well.
If you are planning on using the GIMP or another program that uses
GTK+, you'll need to have the gtk+ package installed.